| /* |
| * Copyright (C) 2015 Square, Inc. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.squareup.okhttp.internal; |
| |
| import com.squareup.okhttp.ConnectionSpec; |
| import java.io.IOException; |
| import java.io.InterruptedIOException; |
| import java.net.ProtocolException; |
| import java.net.UnknownServiceException; |
| import java.security.cert.CertificateException; |
| import java.util.Arrays; |
| import java.util.List; |
| import javax.net.ssl.SSLHandshakeException; |
| import javax.net.ssl.SSLPeerUnverifiedException; |
| import javax.net.ssl.SSLProtocolException; |
| import javax.net.ssl.SSLSocket; |
| |
| /** |
| * Handles the connection spec fallback strategy: When a secure socket connection fails |
| * due to a handshake / protocol problem the connection may be retried with different protocols. |
| * Instances are stateful and should be created and used for a single connection attempt. |
| */ |
| public final class ConnectionSpecSelector { |
| |
| private final List<ConnectionSpec> connectionSpecs; |
| private int nextModeIndex; |
| private boolean isFallbackPossible; |
| private boolean isFallback; |
| |
| public ConnectionSpecSelector(List<ConnectionSpec> connectionSpecs) { |
| this.nextModeIndex = 0; |
| this.connectionSpecs = connectionSpecs; |
| } |
| |
| /** |
| * Configures the supplied {@link SSLSocket} to connect to the specified host using an appropriate |
| * {@link ConnectionSpec}. Returns the chosen {@link ConnectionSpec}, never {@code null}. |
| * |
| * @throws IOException if the socket does not support any of the TLS modes available |
| */ |
| public ConnectionSpec configureSecureSocket(SSLSocket sslSocket) throws IOException { |
| ConnectionSpec tlsConfiguration = null; |
| for (int i = nextModeIndex, size = connectionSpecs.size(); i < size; i++) { |
| ConnectionSpec connectionSpec = connectionSpecs.get(i); |
| if (connectionSpec.isCompatible(sslSocket)) { |
| tlsConfiguration = connectionSpec; |
| nextModeIndex = i + 1; |
| break; |
| } |
| } |
| |
| if (tlsConfiguration == null) { |
| // This may be the first time a connection has been attempted and the socket does not support |
| // any the required protocols, or it may be a retry (but this socket supports fewer |
| // protocols than was suggested by a prior socket). |
| throw new UnknownServiceException( |
| "Unable to find acceptable protocols. isFallback=" + isFallback |
| + ", modes=" + connectionSpecs |
| + ", supported protocols=" + Arrays.toString(sslSocket.getEnabledProtocols())); |
| } |
| |
| isFallbackPossible = isFallbackPossible(sslSocket); |
| |
| Internal.instance.apply(tlsConfiguration, sslSocket, isFallback); |
| |
| return tlsConfiguration; |
| } |
| |
| /** |
| * Reports a failure to complete a connection. Determines the next {@link ConnectionSpec} to |
| * try, if any. |
| * |
| * @return {@code true} if the connection should be retried using |
| * {@link #configureSecureSocket(SSLSocket)} or {@code false} if not |
| */ |
| public boolean connectionFailed(IOException e) { |
| // Any future attempt to connect using this strategy will be a fallback attempt. |
| isFallback = true; |
| |
| if (!isFallbackPossible) { |
| return false; |
| } |
| |
| // If there was a protocol problem, don't recover. |
| if (e instanceof ProtocolException) { |
| return false; |
| } |
| |
| // If there was an interruption or timeout (SocketTimeoutException), don't recover. |
| // For the socket connect timeout case we do not try the same host with a different |
| // ConnectionSpec: we assume it is unreachable. |
| if (e instanceof InterruptedIOException) { |
| return false; |
| } |
| |
| // Look for known client-side or negotiation errors that are unlikely to be fixed by trying |
| // again with a different connection spec. |
| if (e instanceof SSLHandshakeException) { |
| // If the problem was a CertificateException from the X509TrustManager, |
| // do not retry. |
| if (e.getCause() instanceof CertificateException) { |
| return false; |
| } |
| } |
| if (e instanceof SSLPeerUnverifiedException) { |
| // e.g. a certificate pinning error. |
| return false; |
| } |
| |
| |
| // On Android, SSLProtocolExceptions can be caused by TLS_FALLBACK_SCSV failures, which means we |
| // retry those when we probably should not. |
| return (e instanceof SSLHandshakeException || e instanceof SSLProtocolException); |
| } |
| |
| /** |
| * Returns {@code true} if any later {@link ConnectionSpec} in the fallback strategy looks |
| * possible based on the supplied {@link SSLSocket}. It assumes that a future socket will have the |
| * same capabilities as the supplied socket. |
| */ |
| private boolean isFallbackPossible(SSLSocket socket) { |
| for (int i = nextModeIndex; i < connectionSpecs.size(); i++) { |
| if (connectionSpecs.get(i).isCompatible(socket)) { |
| return true; |
| } |
| } |
| return false; |
| } |
| } |